Movable bolster



Jan. 21, 1969 J. A. GEUSS 3,422,662

MOVQBLE BOLSTER Filed Aug. 1, 1967 Sheet 2 of2 FIG.4

l2 v l2 INVENTOR. JOSEPH A. GEUSS ATTORNEYS.

United States Patent 3,422,662 MOVABLE BOLSTER Joseph A. Geuss, Canton,Ohio, assignor to E. W. Bliss Company, Canton, Ohio, a corporation ofDelaware Filed Aug. 1, 1967, Ser. No. 657,587 U.S. Cl. 72-448 7 ClaimsInt. Cl. B21j 13/00; B30b /06 ABSTRACT OF THE DISCLOSURE Apparatus forfacilitating die changing in the metal working press including a wheeledbolster or die carrier movable along tracks from a position outside thepress to a position on the press bed and beneath the ram. The bolsterwheels are arranged to be raised and lowered to permit the bottom of thebolster to be lowered into engagement with the press bed. Additionally,either the bolster or the press are provided with jacks for raising thebolster prior to raising or lowering the Wheels so that the wheelraising and lowering mechanism does not have to lift or lower the weightof the bolster and can, thus, be highly simplified.

The present invention is directed toward the art of presses and, moreparticularly, to an improved die changing apparatus of the movablebolster type.

The invention will be described with particular reference to its use indie changing and metal working presses, however, it will be appreciatedthat the invention is capable of broader application and could beutilized wherever it is desired to lower a wheeled die or materialcarrier into engagement with a subjacent surface.

In the press art it is common practice to provide metal working presseswith wheeled carriers or bolsters which are utilized to move die setsinto and out of the press.

When used for moving die sets into the press, the die set is positionedon the carrier While it is outside the press. The carrier and die set isthen rolled, as a unit, into the press to a position beneath the pressram. At this time, mechanism functions to lower the bottom of thecarrier into engagement with the press bed and thus relieve the load ofthe carrier and dies from the wheels and provide a firm foundation forthe lower die and carrier during subsequent press operation.

One of the common means utilized for selectively lowering or raising thecarrier has been power actuated mechanisms which function to raise andlower the Wheels relative to the carrier. Because of the tremendousweight of the carrier and 'die set, often as much as 50,000 pounds andhigher, the wheel raising mechanisms have been ruggedly built andprovided with relatively powerful actuators. Additionally, sinceactuation of all wheels must take place substantially simultaneously toprevent tilting of the carrier, control systems for the actuators ormechanical interconnections between the various wheels were required.

The present invention overcomes these problems and provides a simplifiedarrangement for raising and lowering the carrier. The mechanism providedallows each wheel raising actuator to be actuated independently withoutrequiring simultaneous actuation of all remaining wheel raisingactuators.

In accordance with the present invention a press of the general typedescribed having a wheeled die carrier provided with wheels movablebetween carrier supporting and non-supporting positions is provided withthe improvement comprising jack means operable when the carrier is inthe press for lifting the carrier and the wheels sufiiciently so thatthe wheels are not supporting "ice the carrier and can, thus, be freelymoved between their carrier supporting and non-supporting positions.

Because the movement of the wheels between their supporting andnon-supporting positions is accomplished with no load on them, they canbe moved by a simply constructed and light weight actuating system. Ifdesired, the wheels can even be manually actuated. Additionally, withthe jack means mounted in the press bed, no special controls orhydraulic or pneumatic systems need be provided on the carrier.

Accordingly, a primary object of the present invention is the provisionof a press having a simplified movable carrier arrangement.

An additional object is the provision of a press having a wheel raisingtype of movable die carrier arrangement which eliminates the need forsimultaneous actuation of the wheel raising mechanisms.

A further object is the provision of a press with a movable die carrierwherein exact locating of the carrier is accomplished by the mechanismused to lower the carrier into engagement with the press bed.

These and other objects 'and advantages will become apparent from thefollowing description when used to illustrate preferred embodiments ofthe invention when read in conjunction with the accompanying drawingswherein:

FIGURE 1 is an elevational view somewhat diagrammatic of a metal formingpress having an improved movable die carrier arrangement constructed inaccordance with one embodiment of the present invention;

FIGURES 2 and 3 are detailed views showing an enlargement of one cornerof the carrier with the wheel raising mechanism in the carriersupporting and carrier non-supporting positions, respectively;

FIGURE 4 is a plan view of the bed of the press shown in FIGURE 1;

FIGURE 5 is a view similar to FIGURE 2 showing a second embodiment ofthe invention;

FIGURE 6 is a cross-sectional view taken on line 6-6 of FIGURE 2;

FIGURE 7 is a cross-sectional view taken on line 7-7 of FIGURE 5; and,

FIGURE 8 is a cross-sectional view taken on line 88 of FIGURE 5.

Referring now to the drawings wherein the showings are for the purposeof illustrating the preferred embodiments of the invention only and notfor the purpose of limiting same, FIGURE 1 shows the overall arrangementof a metal working press A provided with an improved movable bolsterassembly B constructed in accordance with the preferred embodiment ofthe present invention. The press A is shown as a relatively conventionalmetal working press comprised of a bed 10 having an upwardly facingsurface 11 and four vertically extending uprights 12 (see FIGURE 4). Aram 14 is carried by the uprights for vertical movement toward and awayfrom the bed 10. Although not shown in FIGURE 1, the press would, ofcourse, include the usual drive mechanism for driving ram 14.

Broadly. die carrier or movable bolster assembly B includes a relativelyconventional carrier 15 comprised of a main frame 16 having an upperhorizontally extending surface 18 and a lower generally parallel surface20. The carrier is provided with four wheel units 22 mounted generallyat each corner of frame 16. The wheel units are adapted to support thecarrier for guided movement along tracks or gui-deways 26 which extendfrom a position outside the press into and across the press bed. Thetracks or guideways could be of a variety of types but are shown assimple grooves adapted to receive the wheels of the wheel units 22.

The arrangement thus far dscribed is relatively conventional andfacilitates moving die sets into and out of the press. As shown inFIGURE 1, with the carrier 15 positioned outside the press a die setincluding upper and lower die halves 28a and 28!) can be positioned onthe upwardly facing surface 18 of the carrier. Normally, the lower diehalf 28b is positively connected to the carrier such as by the use ofbolts 29. The carrier is then rolled into the press to a positionbeneath the ram 14, as shown in solid lines in FIGURE 1. With thecarrier in position under the ram, the wheels are moved to a raised ornonsupporting position to permit the lower surface 20 of the carrier tobe brought into engagement with the upper surface 11 of the press bed.This removes the load of the carrier and die set from the wheels andprovides a rigid foundation and mounting for the lower die half 28bduring subsequent press operation. Additionally, the carrier is normallybolted or clamped to the press bed in its lowered position. With thecarrier in the lowered position the ram 14 is moved downwardly intoengagement with the top surface of the upper die half 28a and clamped orotherwise connected thereto, such as, by bolts 29a. With the die setthus in position the press is ready for operation. To change die Setsthe above sequence of operation is reversed and the die set and carrierrolled out of the press and a second die set brought in.

The precise arrangement of the wheel raising mechanisms is not ofparticular importance to the invention; however, as shown in FIGURES 2and 3 each of the mechanisms includes a wheel 30 rotatably mounted on ashaft 31 extending between a pair of identical brackets 32. Brackets 32are mounted for selective rotation on a shaft 34 which extends outwardlyfrom the side of the carrier and is supported at its outer end by aplate 36 which extends down from the carrier frame. The brackets 32 areprevented from rotating in a clockwise direction beyond the positionshown in FIGURE 2 by a bracket arm 38 which extends outwardly from theside of the carrier as best shown in FIGURE 6. Extensions 4-0 on thesides of the brackets engage the under surface of the arm 38. However,as shown in FIGURE 3, brackets 32 can be rotated in a counterclockwisedirection to move the wheels 30 to a position wherein the lower surface20 of the carrier can be brought into engagement with the upwardlyfacing surface 11 of the bed.

Any of a variety of means, power actuated or manual, could be utilizedfor selectively moving the wheel brackets to their nonsupportingposition. The particular means utilized in the preferred embodimentcomprise a fluid cylinder 44 which is pivotally connected at one end toa bracket 46 by a pin 48. The piston rod 50 of the cylinder 44 extendsoutwardly to a bracket 52 which is pivotally connected to the wheelsupport bracket by a pin 54. Consequently, actuation of cylinder 44causes the wheels to be pivoted about pivot 34 to move them from theposition shown in FIGURE 2 to the position shown in FIGURE 3.Preferably, the cylinder 44 would be actuated pneumatically; however, itis apparent that it could equally well be hydraulically actuated. Themeans for supplying the necessary pressurized fluid are not shown butcan be built directly in the carrier or mounted on the press andconnected to the carrier by flexible hoses.

As previously discussed this general arrangement can be utilized fordirectly raising and lowering the carrier through actuation of thewheels; however, in such case the actuators 44 must be relatively strongand provided with means causing all wheels to be actuatedsimultaneously. According to the present invention these requirementsare overcome and the wheel raising mechanisms actuated by relativelysmall size cylinders which do not have to be jointly controlled.

According to the invention, this is accomplished by providing jack meanswhich function when the carrier is in the press to lift the carrier andwheels upwardly a very slight amount so that the weight of the carrierand the die set is not supported by the wheels. With the carrier thuslifted. the wheels can subsequently be moved to their non-supportingposition and the jack means actuated to lower the bottom of the carrierinto engagement with the upwardly facing surface 11 of the bed. When itis desired to move the carrier from the press the jack means areactuated to lift the carrier and die set upwardly away from the bed sothat the wheels can be swung to their lowered carrier supportingposition. The carrier can then be rolled out of the press.

Although a variety of different types of jacks could be provided forperforming this function, they preferably comprise hydraulic jackspositioned in the bed at the locations shown in FIGURE 4. As shown inFIGURE 4, four jack means 60 are positioned in the bed at widely spacedlocations. Each of the jack means 60 comprise a hydraulic cylinder 62having a piston 63 slidably mounted therein. A piston rod 64 extendsupwardly from the piston. As is apparent, simply by controlling thesupply of hydraulic fluid through line 65 to a position under the piston63, the movement of piston rod 66 can be controlled to move upwardlyagainst the under side of the carrier frame and lift the carrierupwardly to a position wherein the weight of the carrier is no longersupported by the wheels but is borne by the jacks. The wheel raisingmechanisms can then be actuated to 'move the wheels to the positionshown in FIGURE 3, and the carrier subsequently lowered into engagementwith the press bed.

The present invention also penmits the carrier to be precisely locatedlongitudinally of the track simultaneously with the raising and loweringoperation. As shown in FIG- URES 2 and 3, the upper end of the pistonrod is provided with inclined surfaces 68. A generally V-shaped opening70 conforming to the shape of surfaces 68 is provided in the undersurface of the carrier and arranged to receive the end of piston rod 66.As can be seen, if the carrier is slightly out of line longitudinally,one of the inclined surfaces 68 will engage a side of V-shaped opening70 and, through a wedging action, move the carrier to the exact finalposition. In this manner the jack mean functions to both lift and locatethe carrier and eliminates the need for additional locating means.

Although the above-described arrangement is preferred, it is obviousthat other arrangements for the wheel raising mechanism and the jackscould be provided. A modified arrangement is shown in FIGURES 5, 7 and8. According to this embodiment a set of wheels 76 are mounted at eachcorner of the bolster. Wheels 76 are rotatably connected by axles 77with bracket arms 78 and 80. The bracket arms are respectively mountedfor oscillation on transversely extending shafts 82 and 84. The outerends of the shafts 82 and 84 are supported by extensions 86 and 88 whichextend downwardly from the underside of carrier frame 16. The upper endsof the bracket arms are connected with links 90 and 91 by pivot pins 92and 93. The lower ends of the links are connected through pivot pin 94with the end of a lever arm 95. Lever arm 95 is mounted for oscillationabout a shaft 96 extending from the side of the bolster or carrierframe.

The means for oscillating arm 95 include a fluid cylinder 98 pivotallymounted from a bracket 100 by a pin 102. The cylinders piston rod 104 isconnected through a bracket or clevis 106 and a pin 108 with the upperend of the arm. As can be seen, movement of the piston rod to the left,as viewed in FIGURE 5, causes the wheels to be moved to the dotted lineposition. Alternately, movement of the rod to the right moves the wheelsto their carrier supporting position shown solid. Further movement ofthe wheels beyond the carrier supporting position is prevented by a stopbar 109 which extends laterally from the side of the carrier frame. Asshown, the stop bar is positioned so that the wheels are in what couldbe termed an overcenter position when they are lowered. Consequently,the weight of the carrier prevents any undesired movement of the wheelswhile in this position.

The means for raising the carrier so that the wheels may be more readilymoved between their raised and lowered position includes a jack means110 carried by the carrier frame. As noted with regard to the firstembodiment, any conventional type of jack means could be utilized;however, as shown, the preferred means include a single acting hydrauliccylinder 112 having a piston 113 carried therein and provided with avertically extending piston rod 114. A spring 115 serves to bias piston113 and piston rod 114 to the positionshown in FIGURE 5; however, whenhydraulic fluid is supplied through line 117 the piston and rod aremoved downwardly until the lower end of the piston rod engages the bed,at which time, further supply of hydraulic fluid causes the carrier tobe lifted slightly.

In order to provide exact locating of the carrier simultaneously withthe lifting and lowering operation the lower end of piston rod 114 isprovided with a pair of inclined surfaces 118. Additionally, a V-shapedopening 120 is provided in the press bed for receiving the end of thepiston. Consequently, this arrangement functions in the same manner asthat described with reference to the FIGURES 2 and 3 embodiment, inthat, during movement of the piston rod to raise the carrier, theinclined surfaces 118 will engage the sides of the V-shaped opening 120and any longitudinal misalignment of the carrier be readily corrected.

The invention has been described in great detail sufiicient to enableone of ordinary skill in the press art to make and use the same.Obviously, modifications and alterations of the preferred embodimentwill occur to others upon a reading and understanding of thespecification and it is my intention to include all such alterations andmodifications as part of my invention insofar as they come within thescope of the appended claims.

Having thus described by invention, I claim:

1. In a press having a bed with an upwardly facing surface, a rammovable toward and away from said bed surface; a carrier having wheelson which it is supported for movement along guide means from a positionoutside the press to a position within the press and beneath the ram,said wheels being movable between a first position in which they supportthe lower surface of the carrier at spaced distance above the bedsurface and a second position in which the lower surface can be broughtinto engagement with the bed surface, the improvement comprising: jackmeans operable when said carrier is in said second position for liftingsaid carrier and said wheels sufliciently so that said wheels are notsupporting said carrier and can thus be freely moved between their firstand second positions.

2. The improvement as defined in claim 1 wherein said jack means aremounted in said bed.

3. The improvement as defined in claim 1 wherein said jack means aremounted in said carrier.

4. The improvement as defined in claim 1 wherein said jack means includea plurality of power driven reciprocable rods arranged to be drivenvertically downwardly from said carrier.

5. The improvement as defined in claim 4 wherein said jack meanscomprise a plurality of reciprocable rods arranged to be drivenvertically upwardly from said bed.

6. The improvement as defined in claim 5 wherein at least some of saidrods have tapered end portions, and said carrier has tapered openingsarranged to receive said tapered rods when said carrier is in saidsecond position and said rods are driven vertically upwardly.

7. The improvement as defined in claim 1 wherein said jack meanscomprise a plurality of hydraulic cylinders having vertically extendingpiston rods adapted to en gage said carrier when said cylinders areactuated while said carrier is in said second position.

References Cited UNITED STATES PATENTS 2,913,946 11/1959 Ellrich -2992,988,234 6/ 1961 Barothy 100-299 3,213,739 10/1965 Zingone 100299CHARLES W. LANHAM, Primary Examiner.

G. P. CROSBY, Assistant Examiner.

US. Cl. X.R.

